Soyuz Rocket set to Carry ISS Crew Trio into Orbit

The Soyuz FG rocket topped by the Soyuz TMA-18M spacecraft was rolled to the launch pad at Site 1/5 of the Baikonur Cosmodrome on Monday in anticipation of a Wednesday liftoff to send an international crew of three on their way to the International Space Station.

Sergei Volkov, Andreas Mogensen and Aidyn Aimbetov are set for liftoff at 4:37 UTC to begin a two-day trip to ISS, taking the scenic route as opposed to the six-hour express rendezvous used by most of the recent Soyuz craft traveling to the orbiting outpost.

Soyuz Commander Sergei Volkov is looking forward to his third half-year stay aboard the Space Station. The first Cosmonaut in second generation, Volkov was part of the crew of ISS Expedition 17 and 28/29 – serving as Soyuz commander on both of his previous flights and becoming the youngest person to command ISS.

Aboard Soyuz TMA-18M, Volkov will be joined by two space rookies, Andreas Mogensen of ESA and Aidyn Aimbetov of Kazcosmos, both performing a short-duration mission to ISS and will return next week aboard Soyuz TMA-16M with new space record holder Gennady Padalka.

Once at ISS, Mogensen and Aimbetov will trade places with Scott Kelly and Mikhail Kornienko who are approaching the halfway-mark in their one-year mission. Because the Russian Soyuz craft is only certified to stay on orbit for 215 days, a one-year mission requires a rotation of Soyuz craft with the long-duration crew launching on one and landing on another vehicle. To set up for the Soyuz switch, Padalka, Kelly and Kornienko relocated their Soyuz last week, flying over from the Poisk docking compartment to Zvezda aft to allow Soyuz TMA-18M to use the Poisk module, one of two ISS docking ports in regular use by Soyuz craft.

Coming from an aerospace engineering background, Andreas Mogensen was selected as Astronaut by the European Space Agency in 2009 and was assigned to the short-duration Soyuz Taxi flight in 2013.

Aidyn Aimbetov was selected as one of two Cosmonauts by the Kazakh Space Agency in 2002. Due to financial problems in the Kazakh space sector, Aimbetov’s flight, once planned for 2007, appeared to be far from becoming reality. However, he remained flight-ready and his wait ultimately paid off when Sarah Brightman withdrew from her Space Adventures Tourist Mission, opening a seat that had to be filled on short notice. As part of their short visit to ISS, Mogensen and Aimbetov will complete a busy schedule of scientific experiments and also chime in on current activities ongoing aboard ISS.

Photo: RSC Energia

Processing operations have been rather busy at the Baikonur Cosmodrome as two Soyuz missions were readied for liftoff in a period of just over a month given the shaken up schedule due to the Progress M-27M failure. Soyuz TMA-18M was delivered to the Cosmodrome earlier in the year to undergo thorough stand-alone testing, vacuum tests, electrical testing and specialized testing of the Entry Module. Starting in late July, the Soyuz FG rocket began assembly at the MIK 112 Launcher Integration Facility starting with the attachment of the four boosters to the large Core Stage and preparations of the third stage and Launch Escape Tower.

The three crew members for this flight completed their final pre-flight exams in Star City in late July and early August, going through the usual Space Station simulations as well as simulations aboard the Soyuz in nominal and off-nominal flight situations. Passing their exams with flying colors, the crew was cleared to head to the launch site where they arrived two weeks prior to liftoff to go through a well established process consisting of fit checks, final simulations and procedure reviews and some quiet time before heading off into space.

The crew visited their Soyuz spacecraft – the first time to get familiarized with the situation on board, the second time wearing their Sokol Launch and Entry Suits for a fit check, ingress exercise and a last set of simulations conducted inside their actual spacecraft to serve as a final test for them and the vehicle.

Photo: RSC Energia

While the crew entered a daily routine of tilt table sessions to prepare for microgravity, their Soyuz spacecraft headed to a dedicated processing facility where it was loaded with propellants and pressurized gases needed for its flight to ISS. Once fueling was complete, the Soyuz returned to the Spacecraft Processing Facility to receive the final cargo items and go through another round of testing and inspections.

Over the course of the last week, the Soyuz spacecraft was installed atop its payload adapter, had all of its protective covers removed and was enclosed in its protective launch shroud. The crew paid another visit to the Soyuz on Friday, getting inside one last time before launch day to look at the cargo situation aboard the vehicle. Soyuz TMA-18M was then packed up and moved to MIK 112 for installation on the Soyuz FG rocket.

Over the weekend, the Soyuz FG rocket finished its lengthy assembly process. The TMA-18M spacecraft was attached to the Block I third stage of the rocket as structural connections were put in place, electrical lines were connected and separation systems installed. Next was the installation of the Launch Escape Tower that can pull the Soyuz spacecraft away from the launch vehicle in the event of a major problem during the early portion of the ascent phase. To finish the assembly of the rocket, the Block I stage had its protective engine covers removed and was installed on the Core Stage of the Soyuz FG rocket.

Photo: RSC EnergiaPhoto: Roscosmos

On Monday, Soyuz FG was rolled out of the hangar at MIK 112, being greeted by a colorful sunrise as it made its trip to the historic launch pad at Site 1/5. The three prime crew members were not allowed to watch the rollout in person because it is considered to bring bad luck. The three quarantined crew members spent the past couple of days with their final preparations before leaving Earth for a busy mission. The backup crew members Oleg Skripochka, Thomas Pesquet and Sergei Prokopyev watched the rollout and got an up-close look at the Soyuz rocket, touring the launch pad facilities.

After being positioned at the pad, the Soyuz was put in its vertical launch position using the Transporter-Erector Device. The 50-meter tall Soyuz FG rocket was then secured on the pad so that the Transporter-Erector could be disconnected from the Soyuz and lowered to depart the launch pad.

A series of checks were performed and the Core Stage and Third Stage umbilical towers were moved into position next to the launcher. After a number of checks and preparations, teams began raising the two halves of the Soyuz Service Structure to enclose the launch vehicle and provide access platforms for workers, beginning the nominal L-2 processing flow.

Team will be busy throughout Monday and Tuesday with final preparatory work that includes setup of ground and launch vehicle systems for propellant loading. The Soyuz will be connected to propellant, pressurant and purge umbilicals as well as data lines that interface with the vehicle through the different umbilical towers that are in position on all three stages of the Soyuz until shortly before liftoff. With Soyuz standing tall at the pad, teams will also conduct a series of checkouts of the launch vehicle and spacecraft that will be reviewed by the State Commission Tuesday night to provide the final GO for launch.

For the crew, the last two days ahead of launch are rather quiet with only few final meetings and tagups as well as medical checks that will clear them for flight. They participated in the final pre-flight press briefing on Tuesday before being officially declared ready for flight by the State Commission.

Countdown & Launch Sequence

Photo: RoscosmosPhoto: Tsenki

The three crew members will wake up about nine hours ahead of their liftoff in a schedule that is adjusted slightly given the changed in flight-schedule of the two-day versus six-hour mission profiles. Waking up, the crew members can enjoy their final shower in the comforts of gravity that is followed by whole-body disinfection to protect the carefully maintained environment aboard the Space Station. The crew will have breakfast at the Cosmonaut Hotel and pack up their personal items that will be taken home by their families since their personal cargo is already aboard ISS or packed inside the Soyuz TMA-18M spacecraft.

Out at Site 1/5, engineers will initiate the countdown sequence around eight hours prior to launch with the final set of fueling preparations. The eight-hour countdown process includes all steps needed to transition the Soyuz rocket and spacecraft to a launch configuration. Initial operations include the activation of the Soyuz launcher and spacecraft’s Flight Control System for checkouts.

Once the two vehicles are activated, the Soyuz rocket and spacecraft complete a series of checkouts – communication checks, electrical testing and propulsion system testing is performed in the early stages of the countdown. Completing final hands-on work on the launch vehicle, engineers will install batteries in the booster and remove protective covers from the Soyuz including the booster and core stage engine covers and protective equipment in the interstage.

In the first hours of the countdown, the Soyuz spacecraft will be loaded with final time-critical experiment items for operation on the Russian Segment of the International Space Station.

The three crew members will depart the Cosmonaut Hotel a little over six and a half hours prior to liftoff, signing their respective hotel room doors and receiving the traditional pre-flight blessing. Walking over to their bus, the crew will be greeted by families, fiends and Cosmodrome employees wishing them well on their journey into orbit. Taking a one-hour bus ride over to Side 254, the crew members will be getting ready for medical checks and suit-up operations.

At Site 254, the three crew members go through a final medical check before ingressing their Sokol Launch and Entry suits under assistance by suit technicians to ensure the Sokols can fulfill their task of protecting the crew in the event of a sudden cabin depressurization.

The suits were tested earlier by the crew when completing a simulation inside their Soyuz. Leak checks will be repeated for each crew member, one by one, giving the other two a chance to have a face-to-face conversation with family and friends inside the press room at Site 254.

Five hours and 30 minutes ahead of launch, the Russian State Commission will meet to look at the overall status of the countdown and the results of launch vehicle and spacecraft testing to provide official approval for the beginning of the Soyuz propellant loading sequence. By that time, the tanking carts will have already been rolled up to the pad and hooked up to Ground Support Equipment used to deliver propellants to the Soyuz launch vehicle, loaded via the various umbilical masts connected to the different stages of the rocket to deliver propellant, pressurant and electrical connectivity.

Photo: Tsenki

Overall, the Soyuz FG launcher stands 49.5 meters tall and weighs 305,000 Kilograms when fully fueled. It can lift up to 7,200 Kilograms into Low Earth Orbit using a two-stage stack plus four liquid-fueled boosters clustered around the Core Stage.

Each of the boosters is 19.6m long consisting of a tapered and a cylindrical section with a maximum diameter of 2.68m and a launch mass of 43,410 Kilograms. Each booster is powered by an RD-107A engine delivering 838.5kN of sea level thrust.

The Core Stage is ignited with the boosters and continues to burn after the boosters separate, acting as first and second stage. It is 27.8m tall and 2.95 meters in diameter with a total launch mass of 99,500kg. The core is powered by a 990-Kilonewton RD-108A engine and four verniers for vehicle control. Sitting atop the Core Stage is the third stage that is 6.74m long, 2.66m in diameter and weighs 25,300 Kilograms powered by a four-chamber RD-0110 engine with four vernier thrusters for vehicle control.

Over the course of a two-hour sequence beginning just inside L-5 hours, the boosters, the large Core Stage and the third stage are loaded with a total of 274,140 Kilograms of refined Kerosene and –183°C Liquid Oxygen. Additionally, the boosters and core stage will receive liquid Nitrogen to be heated during flight in order to pressurize the propellant tanks. The boosters and core stage also contain Hydrogen Peroxide that is used to drive the turbopumps of the engines.

While fueling is in progress, technicians complete final close outs of the launch pad and prepare for the arrival of the crew. Propellant loading is expected to be complete at around L-3 hours, allowing the tanking carts to depart Site 1/5.

Around L-3 hours, the crew will depart Site 254, reporting to officials and boarding a bus adorned with plenty of horseshoes for good luck. A 20-minute bus ride will take the trio to Site 1/5 where their Soyuz will be waiting and where the history of crewed space flight began over five decades ago with the launch of Yuri Gagarin.

Getting off their bus, the crew members will have a look at their fully fueled rocket, take a few photos with officials present at the pad and walk over to the Service Structure stairs to wave good-bye and enter the elevator taking them up to their Soyuz for crew ingress.

Climbing into the Soyuz through a hatch inside the Launch Shroud, the crew members will – one by one – enter the Orbital Module through its side hatch before climbing down through the Entry Module’s hatch to reach their Kazbek seat liners in the confined space of the small spacecraft that the crew has to share with cargo and equipment. Sergei Volkov, to command his third Soyuz mission, will enter the Center Seat inside the spacecraft flanked to his left by ESA Astronaut Andreas Mogensen and to his right by Kazakh Cosmonaut Aidyn Aimbetov.

Photo: Gagarin Cosmonaut Training CenterPhoto: RSC Energia

When the crew members are seated, teams will close the Entry Module hatch before the Orbital Module is being closed out by teams to have its hatch is closed as well. Next will be a series of leak checks of the Soyuz completed by pressurizing the individual modules of the spacecraft to ensure the internal and external hatches are holding pressure.

The crew members will begin working through their pre-launch checklist that will take them about one hour to complete beginning with a series of communication checks and the initiation of airflow to the Sokol suits.

The crew will make a number of reconfigurations to put the spacecraft into a nominal configuration for launch. Once the crew members are done with their checklist, the countdown enters a quiet period for them during which they will be entertained with music pumped into the Soyuz through the voice communications system.

60 minutes ahead of launch, the Guidance System is activated and the flight computers receive their flight software 15 minutes later. As hands-on work at the pad wraps up, teams will retract the two halves of the Soyuz Service Structure at L-40 minutes and put all ground systems in a safe configuration. Half an hour before T-0, the Launch Abort System will be activated and switched to automatic mode. The pad will be clear by L-15 minutes.

14 minutes ahead of launch, the Soyuz spacecraft is transferred to battery power and at L-10 minutes, the Soyuz FG inertial guidance system is configured for flight as gyros are uncaged and flight recorders are activated. Entering the Automated Countdown Sequence at T-6 minutes, the Soyuz launch vehicle will begin its final reconfigurations as part of a highly choreographed procedure. Inside the launch bunker near the pad, the launch key will be inserted to give clearance for liftoff.

Soyuz telemetry systems are activated at T-5 minutes and the Commander Controls inside the Soyuz become active. At that point, the crew members will have closed their helmets and switched to suit air.

Three minutes before launch, the five engines of the boosters and core stage are purged with nitrogen before propellant tank pressurization starts at T-2:35. Transfer to internal power occurs one minute before liftoff and Soyuz enables its Auto Sequencer that controls the final countdown events. The third stage umbilical is disconnected at T-50 seconds and the service tower retracts ten seconds later. At T-25 seconds, the umbilical tower of the Core Stage is moved to its launch position.

With the Auto Sequencer in control of the countdown, the Soyuz starts its ignition sequence at T-20 seconds as the turbopumps of the booster and core stage engines soar to flight speed and the engines reach an intermediate thrust level before being throttled up to full thrust for liftoff.

Photo: NASA

Blastoff is set for precisely 4:37:43 UTC, the optimized launch time based on the latest tracking data of the International Space Station. Soyuz has a ten-second launch window to permit the vehicle to link up with the space station. As clocks hit zero, Soyuz will begin rising from its launch pad with a total launch thrust of 422 metric tons, embarking on a nine-minute ascent mission following the usual flight profile.

Making a rare daytime launch, Soyuz FG will begin its pitch maneuver to align itself with the planned ascent trajectory, heading north-east towards the Russian border, homing in on its precise cutoff target to deliver the Soyuz into an orbit at a phase angle of 24.6 degrees to that of the International space Station to begin its fast-track rendezvous.

Soyuz FG passes through Maximum Dynamic Pressure and Mach 1 a little over 70 seconds into the flight, being powered by the RD-107A engines of the boosters and the RD-108A of the core. The Launch Abort System jettisons its Escape Tower at 114 seconds into the mission, marking the transition from low- to mid-altitude abort modes in a system that provides launch abort capability all the way to orbital insertion. The four boosters and their RD-107A engines will burn for 1 minute and 58 seconds consuming a total of 39,600kg of propellants to provide extra boost to the vehicle. After shutdown at an altitude of 49 Kilometers, the boosters are jettisoned for a crash landing 348 Kilometers downrange.

With the boosters tumbling away from the Soyuz rocket, propulsion will only be provided by the Core Stage’s engine, delivering a thrust of 94,400 Kilogram-force. Two minutes and 33 seconds after launch, Soyuz will be over 80 Kilometers in altitude and jettison its protective Launch Shroud giving the crew a view outside through their small Entry Module windows, but the crew members will be focused on their displays, tracking the progress of their ascent into orbit.

Four minutes and 45 seconds into the flight, the Core Stage will shut down its engine, marking the beginning of the hot staging sequence. Two seconds after cutoff, the third stage’s RD-0110 engine will be commanded to ignite. At the same time, pyrotechnic bolts in the interstage will be fired to severe the connection between the empty Core Stage and the upper stage of the Soyuz that will continue powered ascent while the core heads towards re-entry and impact 1,570 Kilometers downrange from the launch site.

The third stage will fire its four-chamber engine and four gimbaling verniers for vehicle control until T+8 minutes and 45 seconds to achieve the planned insertion orbit. Just over two seconds after engine shutdown, the Soyuz spacecraft will separate from its rocket stage which itself will open up an oxygen valve to move away from the spacecraft.

Following spacecraft separation, the Soyuz will put a series of pre-programmed commands into motion to deploy its two power-generating solar arrays and KURS antennas – two events that will be monitored closely after the recent solar arrays deployment issues on Soyuz TMA-14M and most recently TMA-17M.

Photo: NASA

Immediately after spacecraft separation, Soyuz TMA-18M will go through a series of systems checks, pressurize its propulsion system manifolds and enter a stable three-axis orientation. Mission Control will complete a status check and provide the crew with a GO to open their helmets and get out of their seats to ingress the orbital module.

Since Soyuz TMA-18M uses the conventional two-day approach to ISS, the timeline for the crew will not be as packed as it would be for the four-orbit rendezvous. After a series of initial reconfigurations to transition the Flight Control System from launch mode to its free flight configuration, the crew members will get out of their Sokol launch and Entry Suits and set up the orbital module for their two-day commute to the Space Station.

Soyuz TMA-18M will receive an update on its orbital parameters during the mission’s first ground station pass following the completion of the first orbit. During the third orbit of the mission, Soyuz TMA-18M will conduct a pair of engine burns, separated by about half an orbit. The orbital maneuvers are targeting an orbit of 236 by 295 Kilometers to place the Soyuz in the proper orbit to catch up with the Space Station. Another engine burn will take place during the 17th orbit of the mission to put the Soyuz in the appropriate orbit taking it to a position from where it can enter its Automated Rendezvous Sequence.

The Automated Rendezvous Sequence will be initialized at 5:15 UTC on Friday. During the Rendezvous Sequence, the Soyuz will complete more engine burns to link up with the Space Station. A two-way voice link between ISS and Soyuz TMA-18M will be established to provide comm relay to Mission Control. The Space Station will hand to Russian Attitude Control and the KURS Systems of ISS and the Soyuz will be activated.

KURS performance will be verified as part of the standard short test to make sure the system is providing good navigation data to the Soyuz. Once entering the vicinity of ISS, the Soyuz activates its TV system and performs a number of rendezvous impulses with its small DPO thrusters to get ready for the Flyaround Sequence starting at a range of 400 meters at 7:13 UTC.

Making a slow lap around ISS, Soyuz TMA-18M will line up with the Poisk Module. At a distance of 180 meters, the approach will be stopped for a short period of Stationkeeping to give mission controllers a chance to verify good alignment and perform a short systems check.

Once the command for final approach is sent, the Soyuz fires its DPO thrusters to initiate a gentle closing rate. During final approach, Soyuz retracts one of its KURS antennas and keeps itself aligned with the docking port. Contact & Capture is expected at 7:42 UTC (+/-3 minutes) to mark the arrival of Sergei Volkov and two Taxi crew members aboard ISS.

Following docking, the docking probe of the vehicle will retract and hooks & latches will be closed to form a hard mate between Soyuz and ISS. The standard leak check operation will follow to ensure the seal between the Soyuz and ISS is tight. Hatch opening is planned around 10:15 UTC on Friday.